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I need a new perspective: 2", 1.25" or binoviewers

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#1 daslolo

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Posted 14 February 2020 - 03:10 AM

Hello everyone, let me tell you a story.

 

I started with a PST.

I tried 9mm Svony 1.25, the view was awful

Then Celestron bino which wouldn't merge

Then Orion Linear bino which are bright

And Astromania binos which merged, looked good enough that I looked at the sun for at least 20 minutes

 

Then the 8" ACF arrived, so did the clouds which left me no choice but trying it out on land targets.

The binos looked dim, the single plossl 1.25 had not enough immersion (is this what AFOV is?) then I put on the 2" diagonal and. The $200 Meade 21mm showed the secondary (I had the f/6.5 reducer on), the 50$ Meoptex 40mm worked. Once  I had the reducer off both 2" worked and I couldn't tell the difference in quality, looking at tree branches, more immersive on the Meade but also more fidgetty to get the image right, is this due to long eye relief?

I much prefer to have my eye close to the EP, immersed in the image, even if eyelashes grease up the lens.

 

Do you think that daytime viewing shows quality? At night the eye switches to different light cells don't they.

 

I really like the 2". Does the immersion improve with more expensive 1.25?

2" binos sound tempting, the price new is prohibitive and I think with both EP, my nose won't fit, my IPD is 57mm.

 

I'm faffing here. Brain is saturated with the amount of new. Untrained new eye.

 

Looking for immersion above all.

 

I'd like to know what your experience is to get a fresh perspective, getting new ideas in the mix, things I might have missed.

 

Cheers


Edited by daslolo, 14 February 2020 - 03:27 AM.


#2 Jeff Struve

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Posted 14 February 2020 - 08:59 AM

Bino is nice but expensive if ya want top line eyepieces. I only do 100° or greater FoV eyepieces and I find them very immersive.



#3 Baatar

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Posted 14 February 2020 - 09:46 AM

I really like the 2". Does the immersion improve with more expensive 1.25?

 

This is only my view based on EPs I have.  50ish degree plossls will not give immersive views.

 

One would need wider FOV EPs, and although 2" EPs do generally give immersive views some 1.25 eyepieces will do the same.  And they don't have to be super expensive or widest FOV either.

 

ES 68 degree 24 mm will give the widest TFOV in 1.25" format.  I also use 72 degree Delos and 76 degree Morpheus, not super wide EPs, but "immersive" enough for me.  Well, Delos is expensive unless bought used, but Baader Morpheus is affordable new.  I bought my 2 Delos for half price, but in mint conditions.

 

Because of this, I now mostly use 1.25" EPs, easier than changing adaptors, and less heavy.  The only 2" EP I use is ES 68 degree 34mm for the 10" f4.7 Dob, but this is mainly to fit large DSOs (e.g. Pleiades, Andromeda etc.).



#4 MitchAlsup

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Posted 14 February 2020 - 04:48 PM

Bino is nice but expensive if ya want top line eyepieces. I only do 100° or greater FoV eyepieces and I find them very immersive.

Also, because of interpupillary distances, it is hard to get really low power in binoviewers.



#5 daslolo

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Posted 14 February 2020 - 09:02 PM

Also, because of interpupillary distances, it is hard to get really low power in binoviewers.

Meaning the higher the mm the more problem you get... can you explain that? what does the problem look like.



#6 SeattleScott

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Posted 15 February 2020 - 01:18 AM

Immersive is a personal and subjective thing. Some say the 28RKE is immersive, with 45-50 AFOV. Big lens tends to be a factor, as well as AFOV. My 7mm Nagler is many things but I don’t know how immersive it is with that small eye lens. When I think of immersive, I think of something like a ES 92 with a big a** eye lens and huge AFOV, so you feel almost like you are looking out a window into space. The 7mm Nagler is a little more like looking through a peephole. Again it is a personal subjective thing so you really need to figure out what immersive means to you, but in general people associate it with large eye lens and/or wide AFOV.

Binos dim the view by 50% so most people just use them for planetary.

Scott

#7 daslolo

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Posted 15 February 2020 - 01:44 AM

Binos dim the view by 50% so most people just use them for planetary.

I read that the actual loss is 30% due to the brain fusing both images, involving the entire occipital lobe which improves perception, I'd think that 50% loss is when you're at the chemical threshold below which our retina don't trigger pulses. But since I am in Northern WA it's just daytime theory and the PST outputs a lot of light. I noticed far more details in binos with super cheap eyepieces.

Also I tried linear binos and these are far brighter. They split the image in two halves and maybe that's the improvement, although it's still total brightness / 2 reaching the retina so perhaps it's a function of the quality of the splitting mirror vs the prism of other binos.

We shall see if it holds at night.

 

Something I was made aware by someone in stargazer lounge is the length of eyecups are primordial to avoiding kidney beaning of the 100 degree Meades. That would change everything, they're currently unusable.



#8 daslolo

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Posted 20 February 2020 - 01:58 AM

Experience with binos vs 2" eyepieces:

the binos with some 9mm cheapos get me INSIDE Orion, so immersive! I can see a lot of details because it fills my field of vision. Orion is the dimmest I can view.

the 2" ES82 18mm are amazingly good. Immersive, no kidney beaning, crisp and bright orion but also smaller. With an f/6.5 reducer I can see fainter objects like the Andromeda galaxy

 

I love binos, when I lose my self control and buy 2" Siebert binos with a matching set of ES I'll be in heaven.




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